Custom Peptide-Carriers Conjugation Service

Peptide-carriers conjugation is the basic approach for antibody generation against antigenic peptides and haptens. With years of experience, our scientists at Creative Biolabs have developed a series of methods to meet the specific needs of each customer with the best project design.

Peptide-Carriers Conjugation Services

The standard peptides with 15-20 amino acids are often too small to elicit an adequate immune response. To generate antibodies against peptides, it is necessary to couple these peptides to protein carriers. For example, KLH is an ideal carrier protein allowing conjugation to a large number of peptides and eliciting a strong immune response. It is worth noting that antibodies against carrier proteins would also be generated. In this case, affinity purification is necessary for the isolation of antibodies specific to the interest peptides.

BSA Carriers

Bovine serum albumin (BSA) is the plasma protein derived from cattle. As one of the most soluble and stable albumins, BSA consists of 59 lysine residues and has a molecular weight of 67 kDa. Of these, 30-35 of them have primary amines that can react with crosslinkers to couple peptides. Compared with KLH, BSA is more soluble in water, therefore, it is more commonly used in immunoassays. What's more, BSA is the main constituent of fetal bovine serum, which is a common cell culture medium.

KLH Carriers

Keyhole limpet hemocyanin (KLH) is a copper-containing protein that exists in arthropods and mollusks. Its molecule weight range is 4.5 × 10⁵ to 1.3 × 10⁷ Da. Compared with other proteins, KLH presents significantly higher immunogenicity so that it has served as the most commonly used carrier protein. Typically, KLH-conjugated peptides can be used for successful immunization.

OVA Carriers

Ovalbumin (OVA) is a type of protein isolated from hen egg whites. The OVA consists of 385 amino acids and its molecular weight is 42.7 kDa. OVA presents three-dimensional and sequence homology to the serpin superfamily. In biological research, OVA is always used as a second carrier protein to verify the specificity of the antibody.

Peptide-Carriers Conjugates Method

In general, thiol group modifications are used for peptide-carriers conjugation. All modifications with thiol-reactive functional groups can be used for conjugation, the most commonly used groups include iodoacetamide, maleimide, and alkyl halide. In peptide sequence design, we try to avoid including cysteine residues in the peptide in order to add cysteine to the N- or C-terminus of the peptide sequence. For peptide sequences containing internal cysteines, glutaraldehyde would be used for peptide-carriers conjugation. In addition, we can also determine the ratio of peptides to carrier proteins in the conjugate by calculating the amino acid content.

Fig.1 Peptide-protein coupling reagents. (Creative Biolabs Original) Fig. 1 Peptide-protein coupling reagents.

Creative Biolabs offers a full suite of services to help pharmaceutical and biotech companies accelerate their preclinical discovery and development. If you are interested in our conjugation services, please do not hesitate to contact us for detailed information.